Phosphinites,phosphine oxides and process for preparing



United States Patent US. Cl. 260-928 16 Claims ABSTRACT OF THEDISCLOSURE Phosphinites and phosphine oxides of the formulas R R POR R RR PO, R R POR"OP R R and R R P(O)--R P(O)R R and process for making byheating an amino-phosphine of formula R R PNR R with a hydroxyl compoundof formula R OH or HOR --OH to split off ammonia or amine and formphosphinite and isomerizing to phosphine oxide in presence ofisomerization catalyst.

This application is a continuation-in-part of copending application Ser.No. 515,720, filed Dec. 22, 1965, and now abandoned.

Phosphinites and phosphine oxides of the formulas:

wherein R R and R are identical or different hydrocarbon groups and R isa hydrocarbylene group can be prepared according to various well-knownprocesses.

According to one of these processes a dialkylchlorophosphate is reactedwith a Grignard compound. An excess amount of the Grignard compound hasto be used in this reaction in order to avoid the phosphonates, orphosphinates respectively, or the corresponding acids formed in a sidereaction as undesired by-products. There can be prepared onlysymmetrically substituted phosphine oxides by this process. Underforcing conditions (etherbenzene solution mixture) there can also beused a diphenyl-phenyl-phosphonate instead of the halophosphatesmentioned. However, by the possible reaction "with alkyl Grignardcompounds also in this case are obtained only phosphine oxides having atleast 1 to 2 aryl groups and moreover, the yields are not speciallygood. According to a further process, e.g. trimethylphosphite is broughtto reaction with a phenyl Grignard compound. The yields scarcely exceed50%. Despite the limitation to aromatic derivatives which are notdesired here, the formation of tertiary phosphine oxides by condensationof phosphites 'with Grignard compounds needs the oxidation of thetrivalent phosphorus compounds as an additional reaction step.Phosphonic acids and phosphinic acids occur as undesired by-products. Asa rule, symmetric phosphine oxides are formed also when a phosphorylhalide is used as a starting material. Th

3,532,774 Patented Oct. 6, 1970 "ice phosphonic dihalides and phosphinichalides are relatively difficulty accessible starting products and againneed a great excess of Grignard compound. Whereas, for example, fromphenyldichlorophosphine oxide and ptolylmagnesium bromide thecorresponding di-(p-t0lyl)- phenylphosphine oxide is obtainable, thediallyl-phenylphosphine oxide cannot be prepared in this manner.

In a further well-known process a phosphonic acid dihalide (e.g. RP(O)Clis converted into an aminophosphonic acid halide (e.g. RP(O)N(CH Cl),the remaining halogen atom is exchanged for a hydrocarbon group by meansof a Grignard agent, the resulting aminophosphine oxide (e.g.RR'P(O)N(CH is converted by acid hydrolysis into the phosphinic acid andthis is converted by a halogenating agent (e.g. SOCI into its halide,whereupon by a further exchange of the halogen atom by means of aGrignard agent the corresponding tertiary phosphine oxide is obtained.This multistep process comprising several reaction steps has notechnical importance.

Phosphate esters, phosphonate esters and phosphinate esters, as well asphosphoryl halide and substituted phosphoryl halides can be converted insimilar manner into the tertiary phosphine oxides using organolithiurncompounds which are known to be difficult to handle.

Still a further well-known process consists in the decomposition ofquaternary phosphonium compounds in basic solutions. This process offerslimited possibilities only, because always the most electronegativesubstituent is split off.

Other Well-known processes, such as the oxidation of tertiaryphosphines, the isomerization of phosphinites, the hydrolysis oftertiary phosphine dihalides, the reaction of diazoalkanes with possiblysubstituted phosphoryl halides, the addition of secondary phosphineoxides to aldehydes, ketones or activated olefins are mentioned forcompletion only. These are not or very appropriate for the preparationof the following tertiary phosphine oxides having a very specificstructure.

Some of the diphosphine dioxide compounds have also been known hitherto.They have principally been prepared by reacting the hereafter citedreaction components: R PX and MRM, with subsequent oxidation; R PM andXRX, with subsequent oxidation; R PX and XMgRMgX with subsequentoxidation;

Ball CHzM and XllRz (RO) P(O)H and RMgX and XRX; thereby R represents inthese formulae an organic group, X a halogen atom and M an alkali metalatom.

As it is evident, all these processes need a metalorganic compound.

The present invention relates to a process for preparing phosphinitesand phosphine oxides and to certain new phosphine oxides described byFormulas 1, 2, 3 and 4 above. R and R can be saturated or unsaturatedhydrocarbyl groups having up to 24 carbon atoms, and for detergent useare preferably aliphatic having not more than 6 carbon atoms. Fordetergent use R and R of the phosphine oxides of Formula 2 abovepreferably have not more than 4 carbon atoms and are straight-chain andR is preferably straight-chain aliphatic hydrocarbon having from 8 to 24carbon atoms. For detergent one of the R R or R groups of the Formula 4phosphine oxides is aliphatic and has 8 to 24 carbon atoms and the otherR groups have not more than 6 carbon atoms. If an aliphatic R group isunsaturated, it is preferred that it be olefinic unsaturation; however,acetylenic unsaturation can be present.

These aliphatic tertiary phosphine oxides are surfaceandinterface-active compounds which possess a certain solubility in wateror which are easily dispersible by usual dispersion agents. It has beenfound that the solubility, or dispersibility respectively, is improvedwhen at least one aliphatic group shows an olefinic bond.

It has been found that the tertiary phosphine oxides mentioned can beobtained in a simple manner and with good yields by heating anaminophosphine of the general formula:

R R PNR R wherein R and R are defined as above and NR R represents anamino group which is derived from ammonia, a primary or secondary amine,preferably with at least an equimolar amount of an alcohol of thegeneral formula:

R OH

Like the reactions with the alcohol the catalyst can be present from thebeginning to cause the phosphinite to isomerize as it is formed or canbe added after all the phosphinite is formed to cause isomerization tothe phosphine oxide.

The aminophosphines serving as starting products are well-known. Theycan be prepared particularly expediently according to patent applicationSer. No. 371,735, filed June 1, 1964, of the same inventor and the sameapplicant.

Examples of R and R are methyl, ethyl, vinyl, ethynyl, n-propyl,iso-propyl, allyl, propenyl, propargyl, propynyl, n-butyl, iso-butyl,sec-butyl, tert-butyl, methallyl, l-butenyl, crotyl, butadienyl,l-butynyl, 2-butynyl, 1-buten-2- ynyl and higher aliphatic groups havingup to 24 carbon atoms such as undecenyl, dodecyl, myristyl, oleyl,tetracosyl; moreover cycloalkyls, cycloalkenyls and cycloalkynyls suchas cyclopentyl, cyclopentenyl, cyclopentadienyl, cyclohexyl,cyclohexenyl, cyclohexadienyl, cyclohexynyl and greater alicyclic groupshaving up to 12 carbon atoms such as cyclooctyl, cyclododecyl,cyclooctatrienyl, cyclododecatrienyl, bicyclohexyl; moreover aralkyls,aralkenyls and aralkynyls such as benzyl, cuminyl, phenylethyl, styryl,phcnylethynyl, phenylpropyl, 3-phenylallyl, 2-phenylallyl, cinnamyl,l-phenylpropynyl, diphenylmethyl, triphenylmethyl, alpha-naphthylmethyl,beta-naphthylmethyl, alpha-naphthylethyl, beta-naphthylethyl,alpha-naphthylethenyl, beta-naphthylethenyl, alphanaphthylethynyl,beta-naphthylethynyl; moreover alkaryls, alkenylaryls and alkynlarylssuch as tolyl, xylyl, mesityl, duryl, ethylphenyl, cumyl, vinylphenyl,ethynylphenyl, propargylphenyl, propynylphenyl,tert-butylphenyl,l-vinylnaphthyl, 2-vinylnaphthyl, l-ethynylnaphthyl,Z-ethynylnaphthyl; moreover aryls such as phenyl, o-biphenylyl,m-biphenylyl, p-biphenylyl, m-terphenylyl, p-terphenylyl, l-naphthyl,2-naphthyl, Z-anthryl, 9-anthryl, l-phenanthryl, 2 phenanthryl, 3phenanthryl, 4 phenanthryl, 9-phenanthryl etc.

It has been found that the enumerated hydrocarbon groups can also showsubstituents and that these substituents do not hinder the reaction.Examples of possible substituents are: Cl, Br, I, F, OR, SR, COR, CSR,COOR, OCOR, CONR -NR CN, '-NO2, "SOZR, SOzOR, SO2NR2 and =NR.

Examples of the amino group NR R are: NH methylamino, dimethylamino,ethylamino, diethylamino, anilino, N-methylanilino etc. In general, itis preferred that R and R each have not more than 8 carbon atoms andnormally alkyl is preferred; however, it is obvious from Example 2 thateither R or R can be phenyl. As is apparent from the reaction scheme,the amino group is split off in the course of reaction in the form ofammonia or amine. When the evolving amine possesses a lower boilingpoint than the alcohol to be reacted, which is always the case withlower aliphatic amines or ammonia, the course of reaction can beobserved by determining the amount of ammonia or amine recovered. Ingeneral, the choice of the amino group NR R is directed by these aspectsand also by the possibility of the recovery and re-use.

As a further reactant there is used a higher aliphatic alcohol whichpreferably does not show branchings. Examples are octyl alcohol, nonylalcohol, decyl alcohol, undecyl alcohol, lauryl alcohol, tridecylalcohol, myristyl alcohol etc. and higher alcohols having up to 24carbon atoms in the molecule. Branched alcohols, such as isooctylalcohol, 2-ethyl-1-hexanol etc. or unsaturated alcohols, such as oleylalcohol, l-undecenyl alcohol etc. are also included.

When, as an example, diethylphosphinous dimethylamide is brought toreaction with ethyl alcohol in the same manner, no reaction occurs evenat C. Consequently, also the reaction of invention has certain limits,these however lie surprisingly in the desired direction.

Diols, whose hydroxyl groups are attached each to a primary or secondaryaliphatic carbon atoms, are taken into consideration as second reactioncomponents. Examples are 1,2-dihydroxyethane, 1,3-dihydroxypropane, 1,2-dihydroxypropane, 1,4-dihydroxybutane, 1,3-dihydroxybutane,1,2-dihydroxybutane and so on to diols having about 24 carbon atoms inthe chain such as w-dihydroxy tetracosane,1,20-dihydroxy-4,8,13,17-tetramethyleicosane; moreover, cycloaliphaticdiols such as 1,2-dihydroxycyclopentane, 1,2- or1,3-dihydroxycyclohexane, 1,1-dihydroxydicyclohexyl,1,1'-dihydroxydicycloheptyl, 1,4-, 2,3- or 4,8-dihydroxyhexalin;moreover, mixed aliphatic-cycloaliphatic and aliphatic-aromatic diolssuch as 1,2-dihydroxy 1 cyclopropylethane,1,l-dihydroxymethylcyclobutane, 1,1- dihydroxymethylcyclohexane,1,4-di-fl-hydroxyethylbenzene, 1,4-di a hydroxyisopropylbenzene,2,2-dihydroxymethyldiphenyl.

An organic halide, preferably a chloride or bromide, although iodidesare also operable, such as octyl chloride, dodecyl chloride, stearylchloride, stearyl iodide, stearyl bromide, etc. is preferably used as acatalyst. One uses preferably an organic halide of the formula R Brderived from the alcohol being reacted; likewise, the preferredcatalysts where diol reactants are involved, is BrR Br derived from thediol being reacted. In general, an amount of 0.001 to 0.1 mole percentbased on the aminophosphine reactant is sufficient, i.e. a catalyticamount. Also. a greater amount can be used if necessarv.

In practicing the invention it is sufficient to heat at about 100 to 200C. for about /2 hour about equimolar amounts of a dialkylphosphinousamide and the alcohol or diol. But the reaction also proceeds at lowertemperature, although at a lower speed. A temperature at leastsufiicient to split off amine from the amide reactant is necessary;however, obviously the reactants and product must not be heated to sucha high temperature that substantial decomposition of either occurs.Furthermore, it is also possible to apply higher temperatures than 200C. up to 250 C. or higher, because of the relatively high temperatureresistance of the tertiary phosphine oxides. If the isomerizationcatalyst is present, the phosphine oxide is formed and if not thephosphinite, which can then be further heated with the isomerizationcatalyst to form the phosphine oxide. The amine split off is removedmost easily by distilling it 01f from the reaction mixture. It is aconsiderable advantage of the novel process when the isomerizationcatalyst is present that trivalent phosphorus compounds being verysusceptible to oxidation are not formed in significant amounts and thus,the yields of tertiary phosphine oxides are practically quantitative. Ifdesired, the reaction can be blanketed by an inert gas such as nitrogen,argon and the like.

The tertiary phosphine oxides obtained according to the presentinvention can be used as additives to oils, lubricants, detergents andas surface active agents. They possess also biocidal properties and maybe utilized e.g. as herbicides, insecticides, fungicides andbactericides. Moreover they form with metals and metal salts, especiallywith transition metal salts, soluble complex compounds and may beutilized e.g. for the extraction of uranium salts.

Ditertiary diphosphine dioxides which contain greater alkyl groups thanbutyl on each phosphorus atom or greater alkylene groups thanhexamethylene between the two phosphorus atoms, have not been knownhitherto. It has been found that such new compounds are especiallysuitable as washing agents or additives for washing agents, because theyare surface-active and display simultaneously bactericidal properties.

EXAMPLE 1 A mixture consisting of 6 g. (0.045 mole) of (C H PN(CH 8.5 g.(0.045 mole) dodecyl alcohol and 1 drop of dodecyl bromide is heated at130-160 C. for 1% hours. The mixture foams and the theoretical amount ofdimethyl amine distills off. After cooling, the mixture crystallizescompletely; M.P. 45-47 C.

The diethyl-dodecylphosphine oxide can be purified by distillation.Yield 12.3 g. (99.4%); B.P. 151-154 C./ 0.01 mm., M.P. 47-48 C. It isvery soluble in all organic solvents and is hygroscopic.

Analysis.-Calcd for C H OP (percent): C, 70.02; H, 12.86. Found(percent): C, 69.82; H, 13.24.

3113 chemical shift (in methanol) 56.1 p.p.m.

EXAMPLE 2 A mixture consisting of 8.3 g. (0.05 mole) of (CH PN(CH )(C H9.3 g. (0.05 mole) of dodecyl alcohol and 1 drop of dodecyl bromide isheated at 170- 200 C. for 1% hours and the methylaniline which is splitoff is distilled in vacuo. After cooling, the mixture crystallizescompletely. The dimethyl-dodecylphosphine oxide can be purified bycrystallization in light petroleum. Yield 12.0 g. (98%); M.P. 80-82" C.31 chemical shift (in benzene) 39.0 p.p.m.

EXAMPLE 3 In similar manner as Examples 1 and 2 there is obtained with(CH PN(C H tetradecyl alcohol and some tetradecyl bromide thedimethyl-tetradecyl phosphine oxide.

Yield 100% (crude product). The purification 13 achieved byrecrystallization in light petroleum; M.P. 8486 C., 31 chemical shift37.2 p.p.m.

Analysis.-Calcd for C H OP (percent): C, 70.02; H, 12.86. Found(percent): C, 69.62; H, 12.03.

EXAMPLE 4 A mixture consisting of 21.7 g. (0.1 mole) of (n-C H PN(C Hand 17.0 g. (0.1 mole) of 10- undecene-l-ol is stirred in a nitrogenatmosphere at C. for 1 hour. 6.8 g. (94.5%) diethylamine distill off.One drop of dodecylbromide is added to the clear colorless oil and it isheated at C. for 1% hours. The subsequent distillation yields 25.8 g.(82.3%) IO-undecenl-yl-dibutyl phosphine oxide; B.P. 115-118 C./0.5 mm.The clear colorless oil can be also distilled at normal pressure at 240C.

EXAMPLE 5 A mixture of 11.46 g. (0.005 mole) of (CGHS)2PN(CH3)Z and 1.55g. (0.0025 mole) HOCH CH OH is heated at 140 C. for 5 hours in anitrogen atmosphere. There are evolved 2.2 g. (97.6%) of dimethylamine.The reaction mixture is distilled. Besides a small forerun and a residueof 1.8 g. one obtains 7.9 g. (73.6%) of (C H POCH CH OP(C H B.P. 225-227C.

To this distillate are added 4 drops of BrCH CI-I Br and the solution isheated up to 140 C. After A hour the mixture crystallizes completely.The yield is quantitative. The product is recrystallized fromtoluene-acetone. Yield 7.5 g. (95%) of M.P. 256-258.5 C.

Analysis.Calcd for C H O P (430.4) (percent): C, 72.54; H, 5.62. Found(percent): C, 71.08; H, 5.57.

EXAMPLE 6 A mixture of 11.46 g. (0.05 mole) of s 5)2 s)2 and 5.05 g.(0.0025 mole) of HO(CH OH is heated in a nitrogen atmosphere at 140 C.for 4 hours. There are evolved 2.2 g. (97.6%) of dimethylamine. To thecrude liquid diphosphinite are added some drops of BrCH CH Br and thesolution is heated at 140 C. for 8 hours. On cooling the mixturecrystallizes. The product is recrystallized from benzene. Yield 13 g.(91%) of (Cal-192% (CHzhzF (CeH5)2 a.

M.P. -165.5 C.

Analysis.-Calcd for C H O P (570.68) (percent): C, 75.76; H, 7.77. Found(percent): C, 75.23; H, 8.16.

EXAMPLE 7 Amixture of 4.85 g. (0.03 mole) of and 1.36 g. (0.015 mole) ofHO(CH OH is heated at 140 C. in a nitrogen atmosphere for 5 hours. Thereare evolved 2.1 g. (95.5%) of diethylamine. To the crude distillate areadded 2 drops of BrCH CH Br and heated at 140 C. for one hour. Oncooling, the mixture crystallizes. The product is recrystallized frombenzene. Yield 3.8 g. (95%) of (C2H5):IIT(CH2)4IH(C2H5)2 M.P. 112113 C.

Analysis.Calcd for C H O P (266.3) (percent): C, 54.11; H, 10.59. Found(percent): C, 53.48; H, 10.83.

7 EXAMPLE 8 A mixture of 9.7 g. (0.06 mole) of and 6.07 g. (0.03 mole)of HO(CH OH is heated in a nitrogen atmosphere at 140 C. for 6 /2 hours.There are evolved 4.1 g. (93.2%) of diethylamine. To the crudediphosphinite are added 3 drops of BrCH CH CH Br and the solution isheated at 140 C. for 2 hours. On cooling, the mixture crystallizes. Theproduct is recrystallized from benzene. Yield 8 g. (71%) of M.P. 9675.5C.

Analysis.-Calcd for C H O P (378.5) (percent): C, 63.45; H, 11.72. Found(percent): C, 62.4; H, 11.29.

EXAMPLE 9 A mixture of 22.92 g. (0.1 mole) of s 5)2 a)2 and 3.8 g. (0.05mole) of HO(CH OH is heated in a nitrogen atmosphere at 140 C. for 6 /2hours. There are evolved 4.3 g. (95.5%) of dimethylamine. To the crudediphosphinite are added 2 drops of BrCH CH Br and the mixture is heatedat 140 C. for 4 hours. The product is fractionally distilled. Yield 15.8g. (66.5%) of B-P. 001 280-2880 C.; M.P. 195 C.

What I claim is:

1. A process for preparing tertiary phosphine oxides of the formula R RR PO or wherein R and R are each hydrocarbyl groups, R is a hydrocarbylgroup attached to the phosphorus atom by a primary or secondaryaliphatic carbon atom and R is a hydrocarbylene group with eachphosphorus atom being attached by primary or secondary aliphatic carbonatoms, comprising heating in the presence of an isomerization catalystan aminophosphine of the formula R R PNR R wherein R and R are asdefined hereinabove and NR R represents an amino group derived fromammonia or a primary or secondary amine, with a hydroxyl compound of theformula R OH or HOR OH wherein R and R are as defined hereinabove, at atemperature sufiicient to split ofi ammonia or amine and formphosphinite and isomerize the phosphinite to phosphine oxide.

2. A process of claim 1 wherein the reactions are carried out in thepresence of an inert atmosphere.

3. A process of claim 1 wherein when an alcohol is a reactant the molarproportion to aminophosphine is about equimolar, whereas, when a diol isa reactant the molar proportion is about 2:1 aminophosphine to diol.

4. A process of claim 1 wherein the reactions are carried out in therange of 100 to 200 C.

5. A process of claim 1 wherein the hydroxyl compound is R OH, R and Rare straight-chain aliphatic having 1 to 4 carbon atoms, R isstraight-chain aliphatic having 8 to 24 carbon atoms and theisomerization catalyst is of the formula R X wherein R is as definedhereinabove and X is a chlorine, bromine or iodine atom.

6. A process of claim 1 wherein when an alcohol is a reactant, theisomerization catalyst is R X with R being the same as that of thealcohol and X being a chlorine,

8 bromine or iodine atom and when a diol is a reactant the isomerizationcatalyst is XR -X with R being the same as that of the diol and X beinga chlorine, bromine or iodine atom.

7. A process of claim 1 wherein the hydroxyl compound is R OH, R and Rare ethyl, R is n-dodecyl, R and R are methyl, the catalyst is presentduring the reaction of the alcohol and aminophosphine and the catalystis R Br wherein R is n-dodecyl, the molar ratio of alcohol toaminophosphine is about 1:1 and the heating is in the range of to 200 C.

8. A process of claim 1 wherein the hydroxyl compound is R OH, R and Rare methyl, R is n-dodecyl, R is methyl, R is phenyl, the catalyst ispresent during the reaction of the alcohol and aminophosphine and thecatalyst is R Br wherein R is n-dodecyl, the molar ratio of alcohol toaminophosphine is about 1:1 and the heating is in the range of 100 to200 C.

9. A process of claim 1 wherein the hydroxyl compound is R OH, R and Rare methyl, R is n-tetradecyl, R and R are ethyl, the catalyst ispresent during the reaction of the alcohol and aminophosphine and thecatalyst is R Br wherein R is n-tetradecyl, the molar ratio of alcoholto aminophosphine is about 1:1 and the heating is in the range of 100 to200 C.

10. A process of claim 1 wherein the hydroxyl compound is R OH, R and Rare n-butyl, R is 10-undecen-1- yl, R and R are ethyl, the catalyst ispresent during the reaction of the alcohol and aminophosphine and thecatalyst is n-dodecyl bromide, the molar ratio of alcohol toaminophosphine is about 1:1 and the heating is in the range of about 100to 200 C.

11. A process of claim 1 wherein the hydroxyl compound is HOR OH, R andR are phenyl, R is CH CH R and R are methyl, the catalyst is BrCH CH Br,the molar ratio of aminophosphine to diol is about 2: 1, the heating isin the range of 100 to 200 C. and the reactions are carried out in thepresence of an inert atmosphere.

12. A process of claim 1 wherein the hydroxyl compound is HOR -OH, R andR are phenyl, R is (CH R and R are methyl, the catalyst is BrCH CH Br,the molar ratio of aminophosphine to diol is about 2: 1, the heating isin the range of 100 to 200 C. and the reactions are carried out in thepresence of an inert atmosphere.

13. A process of claim 1 wherein the hydroxyl compound is HO-R OH, R andR are ethyl, R is (CH R and R are ethyl, the catalyst is BrCH CH Br, themolar ratio of aminophosphine to diol is about 2:1, the heating is inthe range of 100 to 200 C. and the reactions are carried out in thepresence of an inert atmosphere.

14. A process of claim 1 wherein the hydroxyl compound is HO-R OH, R andR are ethyl, R is (CH R and R are ethyl, the catalyst is BrCH CH- Br themolar ratio of aminophosphine to diol is about 2:1, the heating is inthe range of 100 to 200 C. and the re actions are carried out in thepresence of an inert atmosphere.

16. A compound of the formula R R PO-R O-PR R wherein R and R are eachhydrocarbyl groups and R is a hydrocarbylene group with each phosphorusatom Houben-Weyl, Methoden Organischen Chemie, (1963), being attached byprimary or secondary aliphatic carbon p. 209. atoms. Kosolapotf,Chemical Abstracts, vol. 59, (1963),

References Cited p. 8844d.

2642 461 i T r 260 606 5 5 TOBIAS E. LEVOW, Primary Examiner orns e a3,304,330 2/1967 Yoke et a1 260606.5 BELLAMY Asslstant Exammer OTHERREFERENCES US. Cl. X.R.

Kosolapoff, orsanophosphorus Compounds, 10 260429, 429.1, 606.5, 962,999 p. 102.

